16 research outputs found
Book of Abstracts submitted to the IV Congress of Marine Sciences
The Canary Upwelling System (CUS), a major eastern boundary upwelling system, sustains large crossborder fisheries of small pelagic fish, which poses the question of stock connectivity. Studies suggest that ichthyoplankton transport from the northwest African coast to the Canary Islands (CI) is facilitated by coastal- upwelling associated filaments. Here we analyze connections between larval supply to the CI and sardine and anchovy populations that spawn over the continental shelf. For both species, ichthyoplankton observations (1) at the shelf and (2) near the island of Gran Canaria (GC) are used. Predictions of ichthyoplankton transport to GC are obtained from the Ichthyop Lagrangian transport model, which is forced by a high-resolution hydrodynamic model (ROMS) that reproduces the regional circulation. Results show that upwelling filaments play an important role in the transport of larvae to GC. However, (1) filaments are not the only mechanism, and (2) filament presence does not necessarily imply larval transport. Anchovy and sardine larval presence at GC appears to be independent of the respective adult spawning seasonality. Combining of observed and modeled data does not succeed in reproducing the observed larval patterns at GC. Various hypotheses are proposed to explain this discrepancy in larval transport to GC
The role of neuronavigation in intracranial endoscopic procedures
In occlusive hydrocephalus, cysts and some ventricular tumours, neuroendoscopy has replaced shunt operations and microsurgery. There is an ongoing discussion if neuronavigation should routinely accompany neuroendoscopy or if its use should be limited to selected cases. In this prospective clinical series, the role of neuronavigation during intracranial endoscopic procedures was investigated. In 126 consecutive endoscopic procedures (endoscopic third ventriculostomy, ETV, n = 65; tumour biopsy/resection, n = 36; non-tumourous cyst fenestration, n = 23; abscess aspiration and hematoma removal, n = 1 each), performed in 121 patients, neuronavigation was made available. After operation and videotape review, the surgeon had to categorize the role of neuronavigation: not beneficial; beneficial, but not essential; essential. Overall, neuronavigation was of value in more than 50% of the operations, but its value depended on the type of the procedure. Neuronavigation was beneficial, but not essential in 16 ETVs (24.6%), 19 tumour biopsies/resections (52.7%) and 14 cyst fenestrations (60.9%). Neuronavigation was essential in 1 ETV (2%), 11 tumour biopsies/resections (30.6%) and 8 cyst fenestrations (34.8%). Neuronavigation was not needed/not used in 48 ETVs (73.9%), 6 endoscopic tumour operations (16.7%) and 1 cyst fenestration (4.3%). For ETV, neuronavigation mostly is not required. In the majority of the remaining endoscopic procedures, however, neuronavigation is at least beneficial. This finding suggests integrating neuronavigation into the operative routine in endoscopic tumour operations and cyst fenestrations
The street lamp paradox: Analysing students’ evaluation of teaching through qualitative and quantitative approaches
This paper presents a study about Students Evaluation of Teaching (SET). Student surveys delivered at the end of the academic course is an approach currently applied in all Italian university courses. However, the quality of teaching is a multi-layered phenom-enon whose evaluation might require additional methods. In this study, concerning a course offered during the academic year 2016/2017, we propose the qualitative analysis of students’ final essays, which includes the students’ opinion about teaching quality. The qualitative evaluation of teaching is then compared with the results of the standard SET survey. 48 students filled in the survey, while 47 delivered their final essay (a corpus of about 650 text pages). Our study shows that while the standard survey provides an overall picture useful at institutional level for Quality Assurance (QA), the qualitative approach captures an accurate account of students’ reactions, sensitive to the pedagogical approach adopted. This provides additional information on the students’ perspectives regarding the specific features of the course. Our case study suggests that the integration of traditional SET survey with qualitative teaching evaluation approaches, at least for innovative courses based on socio-constructivist learning, might provide information, overlooked in the Italian SET survey, that is useful for Quality Enhancement (QE) of teaching
The street lamp paradox: Analysing students’ evaluation of teaching through qualitative and quantitative approaches
This paper presents a study about Students Evaluation of Teaching (SET). Student surveys delivered at the end of the academic course is an approach currently applied in all Italian university courses. However, the quality of teaching is a multi-layered phenom-enon whose evaluation might require additional methods. In this study, concerning a course offered during the academic year 2016/2017, we propose the qualitative analysis of students’ final essays, which includes the students’ opinion about teaching quality. The qualitative evaluation of teaching is then compared with the results of the standard SET survey. 48 students filled in the survey, while 47 delivered their final essay (a corpus of about 650 text pages). Our study shows that while the standard survey provides an overall picture useful at institutional level for Quality Assurance (QA), the qualitative approach captures an accurate account of students’ reactions, sensitive to the pedagogical approach adopted. This provides additional information on the students’ perspectives regarding the specific features of the course. Our case study suggests that the integration of traditional SET survey with qualitative teaching evaluation approaches, at least for innovative courses based on socio-constructivist learning, might provide information, overlooked in the Italian SET survey, that is useful for Quality Enhancement (QE) of teaching
EFFECTS OF CLIMATIC CONDITIONS ON CLIMBING PERFORMANCE IN A MOUNTAIN ULTRA-MARATHON RACE
PURPOSE: The purpose of this study was to investigate the influence of climatic conditions on performance in a ~50 km mountainous trail running race. Anecdotal evidence suggests that increased humidity in forested race courses is associated with increased heat stress and decreased performance in ultra-marathoners. We hypothesized that slower climb times would be associated with elevated ambient vapour pressure (VP) and temperature during an ultra-marathon course with heavy tree cover. The rationale follows from body heat loss and cooling being largely dependent on evaporation of eccrine sweat, which is directly proportional to the VP gradient between the ambient air and that on the skin surface. METHODS: Eight healthy males and one female volunteered for the study. Their mean height was 178.3±5.5 cm (mean±SD), weight 71.0±8.3 kg, Body Mass Index 22.4±2.1 ml/kg2, and age 49.7±8.2 years. The office of research ethics at SFU approved the study. Dry bulb (DBT) and wet bulb temperatures were assessed as well as relative humidity (RH) with an electronic humidity sensor. From these ambient VP was determined from a psychometric chart. Wind velocity was assessed with an anemometer. Globe temperature was determined using a Vernon globe thermometer. Remote Omega sensors were used to measure temperature, RH and dew points at three course locations. The GPS coordinates of measurement sites were determined using a handheld instrument. First order linear regression analysis was employed for the analyses and the P value was set at 0.05. RESULTS: Over the race duration there were progressive increases in DB temperature, RH and ambient VP. The mean DBT at the 3 maximum elevations in the race was 21.52±0.57°C and this was positively correlated to mean climb time of 72.26±9.76 min with an R2 = 0.92, p\u3c0.05. The mean RH of 55.39±1.39% was negatively correlated to mean climb time with R2 = 0.47, p\u3c0.05. The mean ambient vapour pressure of 10.73±0.28 mmHg, however, was positively correlated to mean climb time with R2 = 0.40, p\u3c0.10. CONCLUSION: In conclusion, these preliminary results support the hypothesis that increased temperature and ambient vapour pressure are associated with a decrease in performance during strenuous climbs during an ultramarathon on a tree covered course
Steep Shelf Stabilization of the Coastal Bransfield Current: Linear Stability Analysis
International audienceIn situ measurements obtained during the 2010 COUPLING cruise were analyzed in order to fully characterize the velocity structure of the coastal Bransfield Current. An idealized two-layer shallow-water model was used to investigate the various instability processes of the realistic current along the coastal shelf. Particularly studied is how the topographic parameter To (ratio between the shelf slope and the isopycnal slope of the surface current) impacts the growth and the wavelength of the unstable perturbations. For small bottom slopes, when the evolution of the coastal current is controlled by the baroclinic instability, the increase of the topographic parameter To yields a selection of smaller unstable wavelengths. The growth rates increase with small values of To. For larger values of To (To greater than or similar to 10, which is relevant for the coastal Bransfield Current), the baroclinic instability is strongly dampened and the horizontal shear instability becomes the dominant one. In this steep shelf regime, the unstable growth rate and the wavelength selection of the baroclinic coastal current remains almost constant and weakly affected by the amplitude of the bottom velocity or the exact value of the shelf slope. Hence, the linear stability analysis of an idealized Bransfield Current predicts a typical growth time of 7.7 days and an alongshore scale of 47 km all along the South Shetland Island shelf. The fact that these large growth times are identical to the typical transit time of water parcels along the shelf may explain why the current does not exhibit any unstable meanders
Small Mars satellite: A low-cost system for Mars exploration
The Small Mars Satellite (SMS) is a low-cost mission to Mars, currently under feasibility studyfunded by the European Space Agency (ESA). The mission, whose estimated cost iswithin 120 MEuro,aims at delivering a smallLandertoMars using an innovativedeployable(umbrella-like)heat shield concept, known as IRENE (Italian ReEntry NacellE), developed and patented by ALI S.c.a.r.l., which is also the project's prime contractor. The Lander includes two small payloads, i.e.,a dust particle analyzer and an aerial drone. The former isbased on an instrument, developed by the Astronomical Observatory of Capodimonte (INAF-OAC), performing in-situ measurementsof the size distribution and abundance of dust particles suspended in the Martian atmosphere. The drone is being designed by the University of Naples and aims at demonstratingthe feasibility of low-altitude flight in the Martian atmosphere. The project also involves the Space Studies Institute of Catalonia (IEEC), responsible for launch and trajectory design. In the paper, we illustrate the results of the feasibility study of SMS, including adescription of themissionprofile, launch and escape phases, interplanetary trajectory, Mars approach, entry, descent and landing (EDL),and payload deployment and operations. The current baseline envisages launching to LEO with VEGA. Then, a dedicated propulsion module will provide a series of apogee raising maneuvers to place the vehicle on thehyperbolictrajectory to Mars. A targeting maneuver, provided by a cruise stage,will direct the spacecraft to the atmospheric entry point providing initial conditions suitable for the deployment of the heat shield. This will provideaballistic coefficientmuch lower than in previousMarsmissions, thus allowing to reach subsonic conditionswithoutthe use of a supersonic parachute. To demonstrate this, EDL and aero-thermo-dynamic analysesare performed with a 3-DoF modelof the entry trajectoryand high fidelityCFD and DSMC analysis tools. Finally,particular attention is devoted to the description of the deployable shield technology and verification